﻿//  Copyright 2017 Google Inc. All Rights Reserved.
//
//  Licensed under the Apache License, Version 2.0 (the "License");
//  you may not use this file except in compliance with the License.
//  You may obtain a copy of the License at
//
//  http://www.apache.org/licenses/LICENSE-2.0
//
//  Unless required by applicable law or agreed to in writing, software
//  distributed under the License is distributed on an "AS IS" BASIS,
//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//  See the License for the specific language governing permissions and
//  limitations under the License.

using NtCoreLib.Native.SafeHandles;
using NtCoreLib.Utilities.Reflection;
using System;
using System.Runtime.InteropServices;

namespace NtCoreLib;

#pragma warning disable 1591

[Flags]
public enum SessionAccessRights : uint
{
    None = 0,
    [SDKName("SESSION_QUERY")]
    Query = 0x0001,
    [SDKName("SESSION_MODIFY")]
    Modify = 0x0002,
    [SDKName("GENERIC_READ")]
    GenericRead = GenericAccessRights.GenericRead,
    [SDKName("GENERIC_WRITE")]
    GenericWrite = GenericAccessRights.GenericWrite,
    [SDKName("GENERIC_EXECUTE")]
    GenericExecute = GenericAccessRights.GenericExecute,
    [SDKName("GENERIC_ALL")]
    GenericAll = GenericAccessRights.GenericAll,
    [SDKName("DELETE")]
    Delete = GenericAccessRights.Delete,
    [SDKName("READ_CONTROL")]
    ReadControl = GenericAccessRights.ReadControl,
    [SDKName("WRITE_DAC")]
    WriteDac = GenericAccessRights.WriteDac,
    [SDKName("WRITE_OWNER")]
    WriteOwner = GenericAccessRights.WriteOwner,
    [SDKName("SYNCHRONIZE")]
    Synchronize = GenericAccessRights.Synchronize,
    [SDKName("MAXIMUM_ALLOWED")]
    MaximumAllowed = GenericAccessRights.MaximumAllowed,
    [SDKName("ACCESS_SYSTEM_SECURITY")]
    AccessSystemSecurity = GenericAccessRights.AccessSystemSecurity
}

public static partial class NtSystemCalls
{
    [DllImport("ntdll.dll")]
    public static extern NtStatus NtOpenSession(out SafeKernelObjectHandle Handle,
        SessionAccessRights DesiredAccess, [In]ObjectAttributes ObjectAttributes);
}
#pragma warning restore 1591

/// <summary>
/// Class to represent a Session object
/// </summary>
[NtType("Session")]
public class NtSession : NtObjectWithDuplicate<NtSession, SessionAccessRights>
{
    internal NtSession(SafeKernelObjectHandle handle) : base(handle)
    {
    }

    internal sealed class NtTypeFactoryImpl : NtTypeFactoryImplBase
    {
        public NtTypeFactoryImpl() : base(true)
        {
        }

        protected override sealed NtResult<NtSession> OpenInternal(ObjectAttributes obj_attributes,
            SessionAccessRights desired_access, bool throw_on_error)
        {
            return NtSession.Open(obj_attributes, desired_access, throw_on_error);
        }
    }

    /// <summary>
    /// Open a session object.
    /// </summary>
    /// <param name="obj_attributes">The object attributes</param>
    /// <param name="desired_access">Desired access for the object</param>
    /// <param name="throw_on_error">True to throw on error.</param>
    /// <returns>The open result.</returns>
    public static NtResult<NtSession> Open(ObjectAttributes obj_attributes, SessionAccessRights desired_access, bool throw_on_error)
    {
        return NtSystemCalls.NtOpenSession(out SafeKernelObjectHandle handle,
            desired_access, obj_attributes).CreateResult(throw_on_error, () => new NtSession(handle));
    }

    /// <summary>
    /// Open a session object.
    /// </summary>
    /// <param name="obj_attributes">The object attributes</param>
    /// <param name="desired_access">Desired access for the object</param>
    /// <returns>The open result.</returns>
    public static NtSession Open(ObjectAttributes obj_attributes, SessionAccessRights desired_access)
    {
        return Open(obj_attributes, desired_access, true).Result;
    }

    /// <summary>
    /// Open a session object.
    /// </summary>
    /// <param name="name">Name of the object</param>
    /// <param name="root">Optional root directory for lookup</param>
    /// <param name="desired_access">Desired access for the object</param>
    /// <returns>The open result.</returns>
    public static NtSession Open(string name, NtObject root, SessionAccessRights desired_access)
    {
        using var obja = new ObjectAttributes(name, AttributeFlags.CaseInsensitive, root);
        return Open(obja, desired_access);
    }
}
